Testosterone, Total, Males (Adult), Immunoassay
Fasting Required: No

Specimen: Blood

Results: 3-5 Business Days
Note: Result turnaround times are an estimate and are not guaranteed. Our reference lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.

Patient Instructions: Dietary supplements containing biotin may interfere in assays and may skew results to be either falsely high or falsely low. For patients receiving the recommended daily doses of biotin, draw samples at least 8 hours following the last biotin supplementation. For patients on mega-doses of biotin supplements, draw samples at least 72 hours following the last biotin supplementation.

Description: Testosterone is a hormone that causes male characteristics. The blood level is used by men to investigate abnormal sexual development and sexual dysfunction. Small amounts are produced in women's ovaries and levels are tested to evaluate virilization. A drop in testosterone levels can contribute to moodiness, weight gain, loss of muscle mass, and diminished libido.

Testosterone circulates almost entirely bound to transport proteins: Normally less than 1-2% is free. The principal transport protein for testosterone is known as sex hormone binding globulin (SHBG) or testosterone-estradiol binding globulin (TeBG). Testosterone measurements are used to assess erectile dysfunction, infertility, gynecomastia, and osteoporosis and to assess hormone replacement therapy.

This test reports up to a level of <1500(ng/dL).

Limitations: Immunoassay does not provide sufficient sensitivity in detecting low concentrations among non-adults and women.